Method and system for transfer of calls from an ip based phone

ABSTRACT

A system for and method of providing a call transfer is presented. In one exemplary embodiment, the system and method of providing a call transfer may comprise receiving, via a network interface, a call at an IP based phone, the call originating from outside a network of the IP based phone, parsing one or more portions of call information to identify a unique network interface indicator associated with the network interface, receiving a request to transfer the call, and transferring the call to the network interface using the unique network interface indicator.

BACKGROUND INFORMATION

Transferring calls to an appropriate media gateway from a packet basednetwork is challenging. A call from an external network to a packetbased network, such as an IP based network will use a gateway (e.g., amedia gateway), a Session Border Controller (SBC), or another interfacebetween the networks. Calls are frequently transferred back out of thepacket based network (e.g., to another packet based network, to a TimeDivision Multiplexing (TDM) based network, or other network). Thetransferred call often results in a call routed back out of the networkthrough a second media gateway, a Session Border Controller (SBC), orother interface. This results in the call continuing to use resources ofthe network from which it was transferred. For example, two telephony orIP trunks connected to the media gateways or the session bordercontrollers will continue to carry the call as will the correspondingports and a portion of the internal network (i.e., the network fromwhich the call was transferred). This results in wasted resources and aportion of a network being used for an external call (i.e., no partiesto the call are on the network). The use of the network also exposes theadministrators, owners, users, or others associated with the network toliability for a call instead of handing the responsibility off to thenetwork or networks who are parties to the call. For example, there is arisk that the call may be sniffed or otherwise monitored while travelingacross the network.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, together with further objects and advantages, maybest be understood by reference to the following description taken inconjunction with the accompanying drawings, in the several figures ofwhich like reference numerals identify like elements, and in which:

FIG. 1 is a schematic of a system for transferring calls from a packetbased phone, in accordance with an exemplary embodiment;

FIG. 2 depicts a block diagram of a module for a system for transferringcalls from a packet based phone, in accordance with an exemplaryembodiment; and

FIG. 3 depicts a flow chart for a method for transferring calls from apacket based phone.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. It should beappreciated that the same reference numbers will be used throughout thedrawings to refer to the same or like parts. It should be appreciatedthat the following detailed description are exemplary and explanatoryonly and are not restrictive.

An exemplary embodiment provides a system for transferring calls from apacket based phone. The system for transferring calls from a packetbased phone may provide improved call handling.

Referring to FIG. 1, a system for transferring calls from a packet basedphone in accordance with an exemplary embodiment is illustrated. System100 illustrates an exemplary system for improving call handlingassociated with a packet based phone. As illustrated, the system 100 mayinclude one or more networks, such as network 104 and network 108.Networks 104 and 108 may be communicatively coupled to the gateways 106and 120. One or more telecommunication devices 102 a and 102 b may becommunicatively coupled to networks 104 and 108. Other network elements,such as network elements 110, 112, 114, 116, and 118 may becommunicatively coupled to networks 104 and/or 108.

The telecommunication devices 102 may be a wireline phone, a wirelessphone, a satellite phone, Personal Digital Assistant (PDA), computer, orother telecommunication capable devices. The telecommunication devices102 may be communicatively coupled to the network 104 and 108. Thetelecommunication devices 102 and network elements 110, 112, 114, 116and 118 may send and receive data using one or more protocols. Forexample, data may be transmitted and/or received using WirelessApplication Protocol (WAP), Multimedia Messaging Service (MMS), EnhancedMessaging Service (EMS), Short Message Service (SMS), Global System forMobile Communications (GSM) based systems, Time Division Multiplexing(TDM) based systems, Code Division Multiple Access (CDMA) based systems,Transmission Control Protocol/Internet (TCP/IP) Protocols, or otherprotocols and/or systems suitable for transmitting and receiving data.Data may be transmitted and/or received wirelessly or may utilize cablednetwork connections or telecom connections such as an EthernetRJ45/Category 5 Ethernet connection, a fiber connection, a traditionalphone wireline connection, a cable connection or other wired networkconnection. Network elements 110, 112, 114, 116, and 118 may usestandard wireless protocols including IEEE 802.11a, 802.11b and 802.11g.Network elements 110, 112, 114, 116, and 118 may also be communicativelycoupled via protocols for a wired connection, such as an IEEE Ethernet802.3.

Networks 104 and 108 may be one or more of a wireless network, a wirednetwork or any combination of wireless network and wired network. Forexample, networks 104 and 108 may include one or more of a fiber opticsnetwork, a passive optical network, a cable network, an Internetnetwork, a Public Switched Telephone Network (PSTN), a satellite network(e.g., operating in Band C, Band Ku or Band Ka), a wireless LAN, aGlobal System for Mobile Communication (“GSM”), a Personal CommunicationService (“PCS”), a Personal Area Network (“PAN”), D-AMPS, Wi-Fi, FixedWireless Data, IEEE 802.11a, 802.11b, 802.15.1, 802.11n and 802.11g orany other wired or wireless network for transmitting and/or receiving adata signal. In addition, networks 104 and 108 may include, withoutlimitation, telephone line, fiber optics, IEEE Ethernet 802.3, a widearea network (“WAN”), a local area network (“LAN”), or a global networksuch as the Internet. Also networks 104 and 108 may support an Internetnetwork, a wireless communication network, a cellular network, or thelike, or any combination thereof. Networks 104 and 108 may furtherinclude one, or any number of the exemplary types of networks mentionedabove operating as a stand-alone network or in cooperation with eachother. Networks 104 and 108 may utilize one or more protocols of one ormore network elements to which they are communicatively coupled.Networks 104 and 108 may translate to or from other protocols to one ormore protocols of network devices. Although networks 104 and 108 areeach depicted as a single network, it should be appreciated thataccording to one or more embodiments, networks 104 and 108 may eachcomprise a plurality of interconnected networks, such as, for example, aservice provider network, the Internet, a broadcaster's network, a cabletelevision network, corporate networks, and home networks.

Network elements 110, 112, 114, 116, and 118 may each be one or moreservers (or server-like devices), such as a Session Initiation Protocol(SIP) server. Network elements 110, 112, 114, 116, and 118 may betelecom switches, Private Branch Exchanges (PBXs), Voice Response Units(VRUs), announcement servers, voice mail servers and/or voice portals.Network elements 110, 112, 114, 116, and 118 may be VoIP (Voice OverInternet Protocol) enabled devices. Network elements 110, 112, 114, 116,and 118 may include one or more processors (not shown) for recording,transmitting, receiving, and/or storing data. Although network elements110, 112, 114, 116, and 118 are depicted as individual servers, itshould be appreciated that the contents of network elements 110, 112,114, 116, and 118 may be combined into fewer or greater numbers ofservers (or server-like devices) and may be connected to one or moredata storage systems (not shown). Data storage systems may be local orremote to network elements 110, 112, 114, 116, and 118.

Gateways 106 and 120 may be media gateways or Session Border Controllers(SBCs) interconnecting two or more networks. For example, gateway 106and 120 may allow the routing of calls and other data between network104 and network 108. Gateways 106 and 120 may allow the routing of callsbetween different network types such as between a circuit switchednetwork and a packet switched network. In one or more embodiments,gateway 106, gateway 120, or both gateways may be replaced by one ormore switches (not shown) connecting two IP networks. In otherembodiments, gateway 106, gateway 120, or both gateways may be replacedby one or more switches (not shown) connecting two circuit switchednetworks. In some embodiments, gateway 106, gateway 120, or bothgateways may be replaced by one or more switches (not shown) connectingtwo portions of the same network.

According to some embodiments, the telecommunication device 102 b may bean IP phone and network 108 may be an IP based network. Thetelecommunication device 102 b may be capable of identifying and storinginformation identifying call information received during call setup. Forexample, the telecommunication device 102 b may identify and store aunique identifier corresponding to a media gateway, a Session BorderController (SBC), or other interface routing a call to thetelecommunication device 102 b. According to one or more embodiments,call setup information may be used to identify a unique identifier themedia gateway, session border controller, or other interface routing thecall to the telecommunication device. The call setup information used toidentify a unique identifier may include a Session Initiation Protocol(SIP) Re-Invite message information, Session Description Protocol (SDP)information, or other call setup information. The unique identifiercorresponding to a media gateway, a Session Border Controller, or otherinterface routing a call to the telecommunication device 102 b mayinclude an IP address, a fully qualified domain name, or other uniqueidentifier enabling call routing. Telecommunication devices 102 a and102 b may contain volatile memory, non-volatile memory, or other storagefor storing an identifier associated with a media gateway, a sessionborder controller, or other interface.

For example, a user of the telecommunication device 102 b may receive acall from a user of the telecommunication device 102 a. The call may berouted through the gateway 120. The user of the telecommunication device102 b may decide to transfer the call to a destination back on network104, for example, to network element 112. The telecommunication device102 b may use a stored unique identifier such as, for example, the fullyqualified domain name of gateway 120 or an IP address of gateway 120 totransfer the call back to gateway 120. This may ensure that the outboundcall leg from the network 108 goes through the same media gateway,session border controller, or interface as the inbound call leg tonetwork 108 instead of an alternate media gateway such as gateway 106.This may allow a media gateway, session border controller, or interfaceto transfer a call off of network 108 and free the resources of thetransferred call on network 108 as well as the resources of the call ona media gateway, session border controller, or interface. For example,resources may be freed on one or more trunks to or from gateway 120after the call is transferred. Additionally, resources of gateway 120,such as ports, bandwidth, and processing power may also be freed afterthe call is transferred.

Transferring a call may reduce risk to one or more parties associatedwith network 108. For example, an operator, owner, or other partyassociated with network may have some liability or responsibility for acall using its network. There is a risk that the call may be sniffed orotherwise monitored while on the network. By transferring the call offof network resources, the parties associated with the network may nolonger be responsible for the call.

Gateway 120 may receive the call transfer request as a SessionInitiation Protocol (SIP) refer message (e.g., a call transfer requestcompliant with RFC 3515). The Session Initiation Protocol (SIP) refermessage may contain routing information used by the gateway to transferthe call. Gateway 120 may then generate transfer information such asin-band signaling to transfer the call for trunks utilizing in-bandsignaling. If a call is to be transferred to a trunk utilizing asecondary or D (data) channel for signaling, gateway 120 may generate,request, receive or otherwise obtain the appropriate out-of-band controlsignaling to transfer the call. Gateway 120 may use one or methods totransfer a call to a network, which may depend on the type of network.For example, Gateway 120 may use a Two B Channel Transfer (TBCT) iftransferring to a trunk on a circuit switched network. Gateway 120 mayuse a SIP Refer message if transferring to a trunk on an IP basednetwork.

The various components of the system 100 as shown in FIG. 1 may befurther duplicated, combined and integrated to support variousapplications and platforms. Additional elements may also be implementedin the systems described above to support various applications. One ormore portions of system 100 may be implemented in executable softwarecode stored on a computer readable medium.

Referring to FIG. 2, a call transfer module 210 for improved callhandling is depicted, in accordance with an exemplary embodiment. Asillustrated, the call transfer module 210 may contain one or morecomponents including a gateway identification module 212, a calltransfer module 214, and an error handling module 216. The call transfermodule 210 may identify a gateway, a session border controller, oranother interface routing a call to a telecommunication device to allowthe call to be transferred back to the same gateway, session bordercontroller, or interface. According to some embodiments, one or moremodules of call transfer module 210 may be implemented on a IP phonesuch as a soft IP Phone implemented in software on a computer, or ahardware based IP Phone.

The gateway identification module 212 may be capable of identifying andstoring information identifying call information received during callsetup. For example, gateway identification module 212 may identify andstore a unique identifier corresponding to a gateway, a Session BorderController (SBC), or other interface routing a call to atelecommunication device such as telecommunication device 102 b. Callsetup information may be used to identify a unique identifier associatedwith the gateway, session border controller, or other interface. Callsetup information may include a Session Initiation Protocol (SIP)Re-Invite message information, Session Description Protocol (SDP)information, or other call setup information. The unique identifiercorresponding to a gateway, a Session Border Controller (SBC), or otherinterface routing a call to the telecommunication device 102 b mayinclude an IP address, a fully qualified domain name, or other uniqueidentifier enabling call routing to the gateway. The unique identifiermay be stored in volatile memory, non-volatile memory, or other storage.

The call transfer module 214 may use a stored unique identifier such as,for example, the fully qualified domain name of a gateway such asgateway 120 or gateway 106, or an IP address of a gateway to transferthe call back to the gateway. This may ensure that the outbound call legfrom a network, such as network 108, goes through the same mediagateway, session border controller, or interface as the inbound call legto the network instead of an alternate gateway such as gateway 106. Thismay allow a media gateway, session border controller, or interface totransfer a call off of a network and free the resources of thetransferred call on the network as well as the resources of the call ona media gateway, session border controller, or interface. For example,resources may be freed on one or more trunks to or from gateway 120after the call is transferred. Additionally, resources of gateway 120,such as ports and processing power, may also be freed after the call istransferred.

The error handling module 216 may respond to one or more errors createdby a failure to identify a gateway, a failure of a call transfer, afailure of an IP phone, or other errors. The error handling module 216may provide error trapping and one or more error handling actions. Insome embodiments, the error handling module 216 may provide informationabout a failed network component such as the failure of one or more ofnetwork elements 110, 112, 114, 116, and 118. The error handling module216 may provide information about one or more call routing errors.According to one or more embodiments, error handling module 216 mayallow the retry of an operation such as a call transfer. According tosome embodiments, if a stored identifier can not be identified a callmay be transferred to a default gateway, may be dropped, or may lookup agateway based on call origination information.

FIG. 3 depicts a flowchart of a method for a method for transferringcalls from a packet based phone, according to an exemplary embodiment.The exemplary method 300 is provided by way of example, as there are avariety of ways to carry out methods disclosed herein. The method 300shown in FIG. 3 may be executed or otherwise performed by one or acombination of various systems. The method 300 is described below ascarried out by the system 100 shown in FIG. 1 by way of example, andvarious elements of the system 100 are referenced in explaining theexample method of FIG. 3. Each block shown in FIG. 3 represents one ormore processes, methods, or subroutines carried in the exemplary method300. A computer readable media comprising code to perform the acts ofthe method 300 may also be provided. Referring to FIG. 3, the exemplarymethod 300 may begin at block 302.

At block 304, a call may be received at a phone such as, for example, anIP based phone which may be implemented in hardware, software (e.g., anIP communication application running on a computer), or a combination ofthe preceding. The call may be routed from the external network througha session border controller, a media gateway, or an interface.

At block 306, the phone may receive, parse, and store one or moreportions of call information such as, for example, call setupinformation. For example, the phone may parse and store informationuniquely identifying the session border controller, media gateway, orinterface routing the call to the phone. Portions of the call setupinformation parsed may include a Session Initiation Protocol (SIP)Re-Invite message, a Session Description Protocol (SDP) message, orother call setup information. Identifying information parsed from callsetup information may include a fully qualified domain name or an IPaddress of a media gateway or session border controller. Identifyinginformation may be stored in memory or electronic storage associatedwith the phone. The electronic storage may be volatile memory ornon-volatile memory. According to at least one embodiment, identifyinginformation may be stored remote from the phone such as on a gateway ora PBX.

At block 308, the phone may receive a request to transfer the call. Thetransfer request may be input by a user of the phone.

At block 310, the phone may identify the appropriate media gateway,session border controller, or interface to route the call to. Theappropriate media gateway, session border controller, or interface maybe the same as the one handling an inbound leg of the call to the phone.This may prevent a call from coming into a network on one media gatewayor session border controller and exiting a network from a second mediagateway or session border controller, thus using resources of two mediagateways and the IP network unnecessarily after the transfer of thecall.

At block 312, the phone may transfer the call from the network of thephone to a network of a destination location. The phone transferring thecall may identify the media gateway of the inbound leg of the call usingone or more stored unique identifiers of the media gateway obtainedduring call setup. The unique identifier corresponding to a mediagateway, a Session Border Controller (SBC), or other interface routing acall to the telecommunication device may include an IP address, a fullyqualified domain name, or other unique identifier enabling call routingto the media gateway. The transfer may allow a media gateway, a sessionborder controller, or other interface to transfer the call back to theoriginating network and free the resources of the network of the phoneand the resources of media gateway or session border controller. Freedresources may include, by way of non-limiting example, the resources ofthe call on a media gateway, session border controller, or interface.Resources may also be freed on one or more trunks to or from a gateway,session border controller, or other interface after the call istransferred. Resources of a gateway, session border controller or otherinterface freed after the call is transferred may include, by way ofnon-limiting example, ports, processing power, and bandwidth.

Transferring a call may also reduce risk to one or more partiesassociated with a network, such as network 108. For example, anoperator, owner, or other party associated with network may have someliability or responsibility for a call using its network. There is arisk that the call may be sniffed or otherwise monitored while on thenetwork. By transferring the call off of network resources, the partiesassociated with the network may no longer be responsible for the call.

At block 314, the method 300 may end.

In the preceding specification, various preferred embodiments have beendescribed with reference to the accompanying drawings. It will, however,be evident that various modifications and changes may be made thereto,and additional embodiments may be implemented, without departing fromthe broader scope of the invention as set forth in the claims thatfollow. The specification and drawings are accordingly to be regarded inan illustrative rather than restrictive sense.

1. A method, comprising: receiving, via a network interface, a call atan IP based phone, the call originating from outside a network of the IPbased phone; parsing one or more portions of call information toidentify a unique network interface indicator associated with thenetwork interface; receiving a request to transfer the call; andtransferring the call to the network interface using the unique networkinterface indicator.
 2. The method of claim 1, wherein the networkinterface comprises a media gateway.
 3. The method of claim 1, whereinthe network interface comprises a session border controller.
 4. Themethod of claim 1, wherein the unique network interface indicatorcomprises an IP address associated with the network interface.
 5. Themethod of claim 1, wherein the unique network interface indicatorcomprises a fully qualified domain name of the network interface.
 6. Themethod of claim 1, wherein the one or more portions of call informationparsed comprise call setup information.
 7. The method of claim 6,wherein the call setup information comprises a SIP re-invite message. 8.The method of claim 6, wherein the call setup information comprises aSession Description Protocol information.
 9. The method of claim 1,wherein transferring the call is performed using a Two B ChannelTransfer.
 10. The method of claim 1, wherein transferring the call isperformed using a SIP refer request.
 11. A computer readable mediacomprising code to perform the acts of the method of claim
 1. 12. Asystem, comprising; a phone communicatively coupled to a network; atleast one processor communicatively coupled to the phone, wherein the atleast one processor is configured to: receive, via a network interface,a call, the call originating from outside a network of the phone; parseone or more portions of call information to identify a unique networkinterface indicator associated with the network interface; receive arequest to transfer the call; and transfer the call to the networkinterface using the unique network interface indicator.
 13. The systemof claim 12, wherein the network interface comprises a media gateway.14. The system of claim 12, wherein the network interface comprises asession border controller.
 15. The system of claim 12, wherein theunique network interface indicator comprises an IP address associatedwith the network interface.
 16. The system of claim 12, wherein theunique network interface indicator comprises a fully qualified domainname of the network interface.
 17. The system of claim 12, wherein theone or more portions of call information parsed comprise call setupinformation.
 18. The system of claim 17, wherein the call setupinformation comprises a SIP re-invite message.
 19. The system of claim17, wherein the call setup information comprises a Session DescriptionProtocol information.
 20. The system of claim 12, wherein transferringthe call is performed using a Two B Channel Transfer.
 21. The system ofclaim 12, wherein transferring the call is performed using a SIP referrequest.